Use of hyphen in "tomate-cerises

Question

During the exercise, per the bot, "tomates-cerises" is correct.  However, the finished text has "tomates cerises" with no hyphen.  Which is correct?

Accepted Answer

James, 
not sure there is a specific rule for this product although hyphens are most often used between the nouns in French compound nouns. However, tomate(s) cerise(s), sans trait d’union, is in common usage as some supermarket links below show - for these sorts of items a search of shopping sites is very useful ! 
I doubt that either is incorrect though.
 https://www.lawlessfrench.com/grammar/compound-noun-plurals/
 https://www.intermarche.com/produit/tomates-cerises/3250393156052
 https://www.e.leclerc/fp/tomate-cerise-bio-vilmorin-3182670203824
 https://www.carrefour.fr/p/tomates-cerises-rondes-3276558257211 
PS : Je suis actuellement en France avec ma femme pour rendre visite à notre famille française et ce soir on a mangé des « tomates cerises » (achetées à l'Intermarché du coin). Elles faisaient partie de l'apéritif. Leur nom était imprimé sans trait d'union sur la boîte en plastique.

Answer

Hi James, 
To add to Maarten's excellent answer it is because both hyphenated and not hyphenated versions are accepted.
Bonne continuation !